The invention relates to a pipette sampling system that allows for the removal of biological samples from capped containers. More specifically, the invention relates to a pipette tip having a piercing tip attached thereto.
The elucidation of the complete genome sequences of a multitude of prokaryotic and eukaryotic organisms, including in particular, humans, has created the foundation for comprehensive genome analysis. Microarray gene-expression analysis, DNA diagnostics, and gene-based drug discovery, among other applications, rely on knowledge of and access to the genome sequence. The human genome contains approximately three billion base pairs contained within 24 separate chromosomes harboring an estimated total of 30,000 distinct genes, each of which has an average protein-encoding length of about 3,000 base pairs. Further, it has been established that the genetic content comprising the totality of genes identified in the human genome accounts for only about ten percent of the total nucleotide sequence. The function of the remaining portion of the genome is not yet fully understood.
Concomitant with the recent completion of the sequencing of the human genome, a large-scale global effort has evolved, which includes scientists from academic, private, and government research institutions, to understand the functions of all of the novel genes identified, the protein products they encode, and the complex interactions of these components. It is widely believed that this research will have an immediate and profound effect on future understanding of biochemical, genetic, and physiological processes, as well as on the diagnosis and treatment of medical conditions.
In particular, the technology of genotyping is developing at a rapid pace. This technology links various human disease and molecular traits to specific variations found in genes. These variations are defined in terms of a specific section of a gene that, when the sequence of nucleotides in that section changes, a corresponding defect in the protein or other material synthesized from the gene occurs. These portions of the gene are called single-nucleotide polymorphisms, or SNPs. SNPs can be used to predict if an individual is likely to develop a certain disease or if certain drugs will be effective when administered to the individual. This technology is of immense interest to pharmaceutical companies since the SNPs that control responses to a drug can be used to develop tests for the screening of patients prior to the prescription of a drug, which in turn could prove beneficial for the lowering of adverse drug reactions through the identification of susceptible individuals. Further, drug research will be made more efficient since knowledge of SNPs will help define new drugs and will help determine and document the therapeutic effectiveness of a given pharmaceutical compound.
Disclosure of the human genome sequence has created, virtually overnight, a plethora of methods for studying DNA, RNA, and other biological macromolecules such as protein. New whole-genome sequences from a wide variety of organisms are currently being generated at an increasingly high rate. Sequences and the expression patterns of genes are compared and contrasted for differences or similarities in an effort to further the understanding of human biology at genetic, biochemical, and physiological levels. The rapid generation, examination, analysis, and comparative analysis of whole-genome nucleic acid sequences from biological organisms in the art has been termed xe2x80x9cgenomicsxe2x80x9d.
The field of genomics can be divided into two major areas: (a) functional genomics, which attempts to interpret the functions of genes, including the investigation of gene expression and gene control and (b) comparative genomics, which studies the human genome through comparisons to the genomes of non-humans to gain insight into gene function and the evolution of genes, proteins, and organisms. Further, the related discipline of bioinformatics has developed concomitant with the expansion of genomics. This rapidly evolving field has been defined as one that integrates computational approaches for the manipulation and interpretation of the massive amount of nucleotide and protein sequence information currently being generated in the art. The development of new computers, software, and methods of data mining are critical components of this technology.
Although there are a multitude of steps comprising genomic analysis, it is often the case that the initial stages of genomics methodologies are the rate-limiting steps of the complete process. Nucleic acid purification is an example of one such process occurring in the initial stages of genomics methods that can affect the overall speed of the process. In the current art, the purification of nucleic acids is still largely carried out in small batches by trained technicians. Moreover, the technician is limited to processing a small number of samples per day and to producing lower yields of nucleic acids. This limits the ability to generate nucleotide sequence information, exposes the technician to infective agents, risks contamination of the samples, and wastes resources. Therefore, the purification of nucleic acids can represent an important rate-determining step of genomics methodologies.
One technique to increase the efficiency, productivity, and quality of biological macromolecule purification would be to employ automated methods. Several semi-automated methods of sample processing are available for the purification of nucleic acids, but still require human intervention and are not high-throughput. For example, U.S. Pat. No. 5,270,211 relates to a sample tube entry port for an automatic chemical analyzer that facilitates removal of samples by the pipette without exposing the operator to accidental contact with liquid materials in the draw tube.
Fully-automated systems are also available for the purification of nucleic acids but are not widely used due to their inflexibility and high cost. These systems are typically used in dedicated high-volume applications such as those found in large genetics testing laboratories that focus on the isolation and purification of DNA from particular types of samples. Fully-automated systems are generally not used in smaller laboratories where there typically exists a greater diversity of biological sample types from which nucleic acids are purified on a regular basis. Currently, fully-automated systems also suffer from the lack of flexibility in sample volume and typically are designed for small-volume samples. Further, the integrity, purity, concentration, and yield of the nucleic acids tends to be low.
Another initial stage in genomics methodologies is the sampling of biological samples. This step is sometimes referred to as xe2x80x98front-endxe2x80x99 in that it occurs early in the process and further, it can determine the rate of the whole process, particularly when large numbers of tubes must be sampled. Sampling a biological sample, such as blood, is typically performed by aspirating a defined volume of fluid from a container, typically an uncapped test tube. Racks of uncapped sample tubes are common to many clinical laboratories.
Since biological samples are frequently the source of hazardous materials (bacteria, viruses, fungi, biological toxins), they can pose dangers to laboratory technicians and health care workers in many different work settings, including clinical and research laboratories. Further, handling of samples by technicians can often lead to the inadvertent contamination of the biological samples from microorganisms contained on and in the environment around the technician. In other words, the technician must maintain caution and careful handling measures so as not to be contaminated from, or cause contamination to, the sample.
Once the caps are removed from the tubes, the samples are no longer sealed and contamination moving into the tube or contamination being released from the tube can occur inadvertently, even when using the most carefully observed measures. It would be preferable if sampling could occur directly from sealed tube in a manner such that the caps would not have to be removed during the process. Subsequent to sample obtainment, the defined volumes of biological samples are then individually processed through a variety of steps to yield purified biological macromolecules, such as nucleic acids.
In view of the problems in the art mentioned heretofore, there exists a need for a pipette sampling system that allows for the removal of biological samples from sample tubes in a safe, closed-tube, and xe2x80x9chands-freexe2x80x9d manner. There is a further need for a closed-tube pipette sampling system that is automated or semi-automated, and which can be integrated with downstream automated and non-automated processing systems for biological macromolecule purification, including but not limited to the purification of nucleic acid and protein. There exists a still further need for a closed-tube pipette sampling system that can accommodate a flexible range of sample volumes and biological sample types including, but not limited to, whole blood, plasma, spinal fluid, serum, saliva, sputum, urine, feces, Buccal cells, spermatozoa, solid tissue, bacteria, yeast, viral samples, semen, cultured cell lines, plants and combinations thereof. A still further need exists for a pipette sampling system that eliminates or minimizes the potential for sample or operator contamination, is able to sample from a plurality of tubes, and has a low cost.
In accordance with one embodiment of the present invention, a device is provided for removing an aliquot of a biological sample from a closed receptacle comprising said biological sample, comprising a hollow chamber of predefined volume having inner and outer walls and top and bottom ends, a hollow piercing tip having sharp and blunt ends, wherein the blunt end is engaged to the bottom end of the hollow chamber, and a filter barrier engaged to the inner walls of the hollow chamber for preventing cross-contamination of fluids, aerosols, or samples beyond said chamber of predefined volume.
In accordance with another embodiment of the present invention, a method is provided for removing an aliquot of a biological sample from a closed receptacle comprising said biological sample, comprising piercing said closed receptacle with a device comprising a hollow chamber of predefined volume having inner and outer walls and top and bottom ends, a hollow piercing tip having sharp and blunt ends, wherein the blunt end is engaged to the bottom end of the hollow chamber, and filter means engaged to the inner walls of the hollow chamber for preventing cross-contamination of fluids, aerosols, or samples beyond said chamber of predefined volume, and aspirating a predefined volume of said biological sample into said hollow chamber.
In accordance with yet another embodiment of the present invention, a sampling tube system is provided for removing an aliquot of a biological sample from a sealed sample tube comprising said biological sample, comprising a loading arm comprising at least one inflatable membrane holder for reversibly engaging said sample tube for aspiration of the biological sample from the sample tube, a transfer arm comprising a positioning element reversibly engaged to the loading arm for rotating the loading arm and inverting said sample tube, a pipette tip reversibly engaged to the transfer arm comprising a filter barrier, a chamber of predefined volume and a piercing tip for piercing said sample tube, an aspiration tube affixed onto said pipette tip for aspirating said biological sample once the piercing tip has pierced said sample tube, and, optionally, a pipette strip holder for holding said pipette tips.
In accordance with still another embodiment of the present invention, a device is provided for removing an aliquot of biological sample from a sealed receptacle comprising said biological sample, comprising a hollow chamber of predefined volume having inner and outer walls and top and bottom ends, a hollow piercing tip having sharp and blunt ends, wherein the blunt end is engaged to the bottom end of the hollow chamber, a filter barrier engaged to the inner walls of the hollow chamber, a side vent positioned within the hollow chamber and between the filter barrier and piercing tip and a deflector plate separating the hollow chamber and the side vent, wherein the deflector substantially prevents or blocks excess sample from entering into the side vent.
In accordance with a still further embodiment of the present invention, a device is provided for removing an aliquot of biological sample from a sealed receptacle comprising said biological sample, comprising a hollow chamber of predefined volume having inner and outer walls and top and bottom ends, a hollow piercing tip having sharp and blunt ends, wherein the blunt end is engaged to the bottom end of the hollow chamber, a filter barrier engaged to the inner walls of the hollow chamber, and a side vent positioned within the hollow chamber and between the filter barrier and piercing tip, wherein the blunt end of the piercing tip substantially prevents or blocks excess sample from entering into the side vent.
In accordance with yet a still further embodiment of the present invention a device is provided for removing an aliquot of a sample from a sealed receptacle comprising said sample, comprising a hollow chamber of predefined volume having inner and outer walls and top and bottom ends, a hollow piercing tip having sharp and blunt ends, wherein the blunt end is engaged to the bottom end of the hollow chamber, and a filter barrier engaged to the inner walls of the hollow chamber.
In accordance with another embodiment of the present invention, a sampling tube system is provided for removing an aliquot of a sample from a sealed sample tube comprising said sample, comprising a loading arm comprising at least one inflatable membrane holder for reversibly engaging said sample tube for aspiration of the sample from the sample tube, a transfer arm comprising a positioning element reversibly engaged to the loading arm for rotating the loading arm and inverting said sample tube, a pipette tip reversibly engaged to the transfer arm comprising a filter barrier, a hollow chamber of predefined volume and a piercing tip for piercing said sample tube, an aspiration tube affixed onto said pipette tip for aspirating said sample once the piercing tip has pierced said sample tube, and optionally, a pipette strip holder for holding said pipette tips.
In accordance with a further embodiment of the present invention, a method is provided for sampling one or more samples from sealed sample tubes comprising said samples, comprising the steps of transferring said sample tube from a sample rack to a loading arm, wherein said sample tube is in an upright position, piercing said sample tube with a pipette tip comprising a piercing tip, inverting the pierced sample tube to a degree sufficient to maintain contact of the sample and the closure for a time sufficient to allow sample collection, aspirating said fluid from the pierced sample tube into a chamber within the pipette tip, reinverting the pierced tube to the upright position, and withdrawing the piercing tip from the sample tube.
In accordance with still another embodiment of the present invention, a device is provided for removing an aliquot of a sample from a sealed receptacle comprising said sample, comprising a hollow chamber of predefined volume having inner and outer walls and top and bottom ends, a hollow piercing tip having sharp and blunt ends, wherein the blunt end is engaged to the bottom end of the hollow chamber, a filter barrier engaged to the inner walls of the hollow chamber, a side vent positioned within the hollow chamber and between the filter barrier and piercing tip, and a deflector plate separating the hollow chamber and the side vent, wherein the deflector plate substantially prevents or blocks excess sample from entering into the side vent.
In accordance with still another embodiment of the present invention, a device is provided for removing an aliquot of sample from a sealed receptacle comprising said sample, comprising a hollow chamber of predefined volume having inner and outer walls and top and bottom ends, a hollow piercing tip having sharp and blunt ends, wherein the blunt end is engaged to the bottom end of the hollow chamber, a filter barrier engaged to the inner walls of the hollow chamber, and a side vent positioned within the hollow chamber and between the filter barrier and piercing tip, wherein the blunt end of the piercing tip substantially prevents or blocks excess sample from entering into the side vent.
In accordance with yet another embodiment of the present invention, a method is provided for preventing cross-contamination of an aliquot comprising a sample while removing said aliquot from a sealed receptacle comprising said sample, comprising the steps of piercing said sealed receptacle with a device comprising a hollow chamber of predefined volume having inner and outer walls and top and bottom ends; a hollow piercing tip having sharp and blunt ends, wherein the blunt end is engaged to the bottom end of the hollow chamber; and filter means engaged to the inner walls of the hollow chamber for preventing cross-contamination of fluids, aerosols, or samples beyond said hollow chamber, and aspirating a predefined volume of said sample into said hollow chamber.
One object of the current invention is to provide a pipette sampling system that allows for the removal of biological samples from sample tubes in a safe, closed-tube manner such that the risk of sample- or operator-contamination is eliminated. Another object of the current invention is to provide a closed-tube pipette sampling system, that is automated, semi-automated or manual, which can be integrated with downstream automated and non-automated processing systems for biological macromolecule purification, including but not limited to the purification of nucleic acid and protein. A further object of the current invention is to provide a closed-tube pipette sampling system that can accommodate a flexible range of sample volumes and biological sample types including, but not limited to, whole blood, plasma, spinal fluid, serum, saliva, sputum, urine, feces, Buccal cells, spermatozoa, solid tissue, bacteria, yeast, viral samples, semen, cultured cell lines, plants and combinations thereof. A still further objective of the current invention is to provide a closed-tube pipette sampling system that can sample from a plurality of tubes, employs disposable pipette tips and disposable piercing tips, has a low cost, and is suitable for a genomics platform.
The present invention encompasses methods and components for a pipette sampling system that provides closed-tube sampling of samples from sample tubes comprising a wide variety of sample types. Such sample types may be biological such as, for example, whole blood, plasma, spinal fluid, serum, saliva, sputum, urine, feces, Buccal cells, spermatozoa, solid tissue, bacteria, yeast, viral samples, semen, cultured cell lines, plants and combinations thereof. The sample types may also be chemical such as, for example, reagents, catalysts and the like. Indeed, a skilled artisan would readily understand that any sample type capable of being aspirated out of a sample tube may be utilized by the present invention.
The components comprising the current invention include, but are not limited to, a sample tube, preferably but not limited to a Vacutainer(trademark) (Becton Dickinson), a pipette tip, preferably a disposable pipette tip, and a sampling tube system, preferably requiring no human intervention. Further, the invention can be automated or semi-automated, can provide sampling from a plurality of sample tubes, and can be integrated with downstream automated and non-automated processing systems for biological macromolecule purification, including but not limited to, the purification of nucleic acid and protein.
In one embodiment, the pipette tip comprises a main chamber of defined volume, a filter barrier, and a piercing tip. Preferably, the piercing tip is designed to penetrate a closure of the sample tube without the destruction or removal of the tube closure. The piercing tip can be made of any non-reactive material known in the art, including, for is example, stainless steel, plastics, polypropylene and polystyrene.
The sample tube is comprised of a hollow chamber with an orifice at the top end and a closed surface at the bottom end. It is preferable that the sample tube is a vacuum collection tube such as that embodied by, but not limited to, a Vacutainer(trademark) (manufactured by Becton Dickenson). Preferably, the filter barrier of the pipette tip is sufficient to prevent cross-contamination of samples, fluids, or aerosols and/or fluid uptake or movement beyond the chamber, such as into instrument lines or components. More preferably, the filter barrier is a hydrophobic sterilizable filter barrier, such as, for example, Porex.(trademark) Preferably, the pipette tip and the piercing tip are designed and adapted to pierce the closure of the sample tube, are disposable, and come pre-sterilized.
The pipette tip allows aspiration of aliquot samples from sample tubes. Such aliquots can be from about 1 xcexcl to about 5 ml in volume, preferably from about 5 xcexcl to about 1 ml, or most preferably from about 20 xcexcl to about 100 xcexcl. Preferably, the pipette tip is designed and adapted for use in the closed-tube pipette sampling system and downstream automated and non-automated processing systems for biological macromolecule purification.
The present invention further comprises a sampling tube system that allows the pipette sampling system access to a sample contained in a tube so as to obtain a defined volume of the sample. The defined volume can be from about 1 xcexcl to about 5 ml, or preferably from about 5 xcexcl to about 1 ml, or most preferably from about 20 xcexcl to about 100 xcexcl. Further, it is preferable that the sample tube is sealed with a closure barrier that seals the tube and prevents the sample from leaking, spilling, or releasing aerosols. An example of a tube system available in the art that could be used is the Vacutainer(trademark) tube, a type of vacuum collection tube (Becton Dickinson). These tubes are provided with ordinary rubber stoppers or with rubber stoppers covered by a plastic Hemogard(trademark), which provides an additional protective collar to further prevent accidental contact with sample fluids on the surface of the stopper. Vacuum collection tubes available in the art are typically deigned to contain volumes of sample fluid ranging from 3 ml to 10 ml and have outside diameters of 10.25 mm to 16 mm and a length of 64 mm to 100 mm. The tubes can include a label, which can be made of a composition known in the art including, but not limited to, paper or plastic. Preferably, the label is a barcode.
In a preferred embodiment, the sampling tube system allows for access to the sample in an automated or semi-automated manner. More preferably, access is via the pipette tip of the present invention, comprising the piercing tip, the chamber of predefined volume, and the filter barrier. Most preferably, the sampling tube system allows closed-tube handling of the sample and operates in a manner that does not require human intervention.
The sampling tube system contains a loading arm that holds and manipulates the sample tube via inflatable membranes holders, wherein the loading arm allows proper positioning of the sample tube closure and the piercing tip of the pipette tip so that aspiration of the sample through the pierced closure occurs. A transfer arm rotates and moves the loading arm to sample multiple tubes in a serial or parallel manner.
The present invention encompasses a pipette sampling system, designed to utilize in a coordinated and automated or semi-automated manner with regard to function and timing, the sample tube, the pipette tip, and the sampling tube system for the sampling of biological samples from closed-tubes. Further, the invention can provide sampling from a plurality of sample tubes and can be integrated with downstream automated and non-automated processing systems for biological macromolecule purification, including but not limited to, the purification of nucleic acid and protein.